TO category:

Locksmith work - general

Basic plumbing operations and their purpose

Metalworking operations refer to the processes of cold metal cutting. They are carried out both manually and with the help of mechanized tools. The purpose of metalworking work is to give the workpiece the shape, size and surface finish specified in the drawing. The quality of plumbing work performed depends on the skills of the mechanic, the tool used and the material being processed.

Metalworking technology contains a number of operations, which include: marking, chopping, straightening and bending metals, cutting metals with a hacksaw and scissors, filing, drilling, countersinking and reaming holes, threading, riveting, scraping, lapping and finishing, soldering and tinning , bearing filling, gluing connection, etc.

When manufacturing (processing) metal parts using the metalwork method, the main operations are performed in a certain order, in which one operation precedes the other.

First, metalworking operations are carried out to manufacture or correct the workpiece: cutting, straightening, bending, which can be called preparatory. Next, the main processing of the workpiece is performed. In most cases, these are cutting and filing operations, as a result of which excess material is removed from the workpiece.

layers of metal and it receives the shape, dimensions and condition of the surfaces, close to or coinciding with those indicated in the drawing.

There are also machine parts that require the processing of scraping, lapping, finishing, etc., during which thin layers of metal are removed from the part being manufactured. In addition, during the manufacture of a part, it can, if required, be connected to another part, together with which it is subjected to further processing. To do this, the operations of drilling, countersinking, threading, riveting, soldering, etc. are performed.

All of the listed types of work relate to basic metalworking operations.

Depending on the requirements for finished parts, additional operations may also be performed.

Their purpose is to give metal parts new properties: increased hardness or ductility, resistance to destruction in gases, acids or alkalis. Such operations include: tinning, enamel coating, hardening, annealing, electrostrengthening, etc.

When determining the processing sequence, they take into account the form in which the parts (blanks) arrive; rougher processing always precedes final (finishing) processing.

Fitting and assembly work at a machine-building enterprise is a set of operations for connecting parts in a strictly defined sequence to obtain a mechanism or machine that meets the requirements for them technical requirements. During assembly, all basic types of metalwork are used, including fitting assembled parts into assemblies, followed by adjustment and checking the correct operation of mechanisms and machines. The build quality of a machine affects its durability and operational reliability, since the fewer errors allowed during assembly, the greater the performance and better specifications machines and mechanisms.

Mechanical repair work is aimed at maintaining the operability of equipment. Equipment repairs are carried out at enterprises primarily in order to eliminate machine defects that impede their normal operation. Worn parts are replaced during repairs with new ones or restored to their original sizes in various ways.

Technical progress and the associated equipping of enterprises with the latest technology, as well as implementation in production processes advanced technology impose new requirements on existing equipment, therefore, simultaneously with the repair of machines at plants and factories, a lot of work is being done to modernize (update) it. Equipment modernization aims to increase the speed and productivity of machines, the power of their engines, reduce idling time and auxiliary operations, create a narrow specialization, as well as expand the technological capabilities of certain types of equipment and increase the wear resistance of machine parts. Work on modernizing equipment is carried out at the plant according to a specific plan.

The volume of metalworking largely characterizes the technical level of the technology used and depends on the nature of production. At machine-building plants that produce heterogeneous products in small quantities (unit production), specific gravity plumbing work is especially great. Here the locksmith is required to perform a wide variety of locksmith work, i.e., to be a general-purpose locksmith. If necessary, he repairs and installs machines, manufactures fixtures, etc.

In mass production, where homogeneous parts are manufactured in large batches, the accuracy of machining increases and, accordingly, the volume of metalworking work is somewhat reduced. The work of mechanics continues to be necessary even in mass production factories, where homogeneous products are produced in large quantities and for a long time (a year, two, etc.).

In all factories and plants, regardless of the type of production, mechanics are needed to make dies, fixtures and tools, to perform repairs and installations industrial equipment, sanitary and technical work, industrial ventilation, etc. You can’t do without mechanics in modern agriculture; here they repair tractors, combines and other equipment.

Metalworking technology contains a number of basic operations, such as marking, chopping, straightening and bending metals, cutting metals, filing, drilling, countersinking, countersinking and reaming holes, threading, riveting, lapping and finishing, soldering, etc. Most of these operations include for metal cutting processing.

3.1 Marking

Marking is the operation of applying lines (scores) to the surface of the workpiece, showing, according to the drawing, the contours of the part or place to be processed. Markup is divided into:

Linear (one-dimensional) – along the length of rods, rolled products, strip steel,

Planar (two-dimensional) - for workpieces made of sheet metal,

Spatial (volumetric, three-dimensional) – for volumetric workpieces.

Special marking tools include scribers, center punches, marking compasses, and surface planers. In addition to these tools, hammers, marking plates and auxiliary devices are used: pads, jacks, etc.

Figure 6 Scribbler

Scribblers (Figure 6) are used to draw lines on the marked surface of the workpiece. They are made from tool steel U10 or U12 (hardness HRC 58-62).

Core punches (Figure 7) are used to apply recesses (cores) to previously

Figure 7 Kerner

marked lines so that the lines are clearly visible and are not erased during the processing of parts.

A center punch is a rod made of tool carbon steel U7, U8 (HRC 52-57) with a length of 100-160 mm and a diameter of 8-12 mm. The sharpening angle is usually 60°, for more precise markings - 30-45°, for the centers of future holes - 75°.

Marking (metalwork) compasses are similar in design to drawing compasses.

Thicknesser (Figure 8) is used for applying parallel vertical and horizontal marks. IN Lately A height gauge with a sharp tip is more often used.

Planar and especially spatial marking of workpieces is carried out on marking plates.

The marking plate is a cast iron, horizontal working surface and the side edges of which are very precisely processed.

A template is a device used to make parts or check them.

after processing. Pattern marking is used in the production of large batches of identical parts. It is advisable because labor-intensive and time-consuming marking according to the drawing is performed only once during the manufacture of the template. All subsequent operations for marking blanks consist of copying the outlines of the template. In addition, the manufactured templates can be used to control the part after processing the workpiece.

3.2 Straightening and bending of metals

Straightening is an operation to eliminate defects in workpieces and parts in the form of concavity, convexity, waviness, warping, curvature, etc. Its essence lies in the compression of the convex layer of metal and the expansion of the concave one.

The metal is straightened both in cold and heated states. The choice of one or another straightening method depends on the amount of deflection, size and material of the workpiece (part).

Straightening can be done manually (on a steel or cast iron leveling plate) or machine (on leveling rollers or presses).

The correct slab, like the marking slab, must be massive. Its dimensions can be from 400400 mm to 15003000 mm. The slabs are installed on metal or wooden supports, ensuring the stability of the slab and its horizontal position.

To straighten hardened parts (straightening), straightening heads are used. They are made of steel and hardened. The working surface of the headstock can be cylindrical or spherical with a radius of 150-200 mm.

Manual straightening is carried out with special hammers with a round, radius or insertable soft metal striker. Thin sheet metal is straightened with a mallet (wooden hammer).

The straightening is checked “by eye”, and if there are high requirements for the straightness of the strip, with a straight edge or on a test plate.

Shafts and round blanks large sections are straightened using a manual screw or hydraulic press.

Metal bending is used to give the workpiece a curved shape according to the drawing. Its essence lies in the fact that one part of the workpiece is bent relative to the other at a given angle. Manual bending is carried out in a vice using plumber's hammer and various devices.

Bending of thin sheet metal is done with a mallet.

When plastic deformation of metal occurs during bending, the elasticity of the material must be taken into account: after the load is removed, the bending angle increases slightly.

The manufacture of parts with very small bending radii is associated with the danger of rupture of the outer layer of the workpiece at the bending point. The size of the minimum permissible bending radius depends on the mechanical properties of the workpiece material, bending technology and surface quality.

Pipe bending is done with or without filler (usually dry river sand). The filler protects the pipe walls from the formation of folds and wrinkles (corrugations) in places of bending.

studfiles.net

GBPOU RM "Saransk Polytechnic College" Ruzaevka.

Summary for the lesson “Basic metalworking operations in welding production”

File: lesson notes

Routing No. 1 PM05. “Performing work according to the worker’s profession”

Subject: General information about metalworking operations used in assembly and welding production.

Purpose: To become familiar with the basic metalworking operations used in the manufacture of a welded product.

Lesson type – practical lesson.

Lesson teaching method - partially search

Lesson objectives:

Educational:

The student must be able to:

Correctly determine the loads on welds; - draw up diagrams of loads on welds.

Educational:

To develop in students the ability to make independent technical decisions, attentiveness, and respect for their chosen profession.

Developmental:

To form in students an information-professional worldview and a desire to learn new things.

To stimulate interest in the discipline, to reveal the relationship of the discipline with other professional disciplines.

The form of training is group.

The teaching method is practical.

Material, technical and didactic equipment of the lesson: - multimedia installation, electronic textbook materials, guidelines for completing the work

During the classes

1. Updating basic knowledge, abilities, skills and personality traits

Checking the availability of students according to the payroll - report; - Setting lesson goals; - Issuing individual assignments for practical work.

2. Formation of new knowledge, abilities, skills and personality traits

Metalworking is the processing of metals, usually as a complement to machining or as a finishing touch to manufacturing. metal products connecting parts by welding, assembling machines and mechanisms, as well as their regulation. Locksmith work is performed using manual or mechanized metalworking tools or on machines.

Locksmith work is used in various types of production and they are united by a single technology for their implementation.

Basic plumbing operations can be divided into several groups according to their purpose:

Fig. 1 Main groups of plumbing operations

The operations of each group have their own accuracy class, so in the process of work you should clearly understand what processing accuracy is necessary in the final result of metalworking. In enterprises or workshops that produce a variety of welded products, the versatility of performing various metalwork operations is required.

The quality of the welded joint largely depends on the preparation of the metal and the assembly of the product for welding.

The base metal intended for the manufacture of welded structures is cleaned, marked into individual parts, and the necessary edge profiling is performed.

Cleaning is an operation that is used to remove from the metal surface preservatives, contaminants, cutting fluids, rust, scale, burrs and burrs that complicate the welding process, cause defects in welds and interfere with application protective coatings.

Straightening is an operation to eliminate deformations of rolled sheet steel and profile metal, straightening blanks of parts that have dents, bulges, waviness, warping, curvature, etc. The metal is straightened both in a cold and heated state. The choice of method depends on the deflection, size and material of the product.

Marking is the transfer of full-size dimensions of a part from a drawing to metal. In addition, when welding, marking lines (marks) are applied to the surface of the workpiece, which determine the installation location of individual parts when assembling components and structures.

There are:

1. Planar markings.

2. Spatial marking.

Metal cutting is the operation of separating metal into parts.

Depending on the shape and size of the workpieces or parts, cutting is carried out manually - with hand scissors, hand hacksaws, lever scissors. Cutting can also be carried out using oxygen torches along the intended contour line of the part manually or with special purpose gas cutting machines. Cutting on mechanized machines is more productive and has a high quality cut. However, it is advisable to perform mechanical cutting when preparing parts of the same type, mainly with a rectangular cross-section.

Bending is a method of processing metal by pressure, in which a workpiece or part thereof is given a curved shape.

Chopping is a metalworking operation in which, using a cutting tool (chisel, etc.) and a percussion tool (machinery hammer), excess layers of metal are removed from the surface of a workpiece or part or the workpiece is cut into pieces. In addition, chopping is used when it is necessary to remove burrs, defects or remove part of the metal.

Filing is the removal of a layer of metal from the surface of a workpiece using a special cutting tool - a file.

Using files, a mechanic gives parts the required shape and size, fits parts to each other, prepares the edges of parts for welding and performs other work.

3. Summing up the lesson (5 min)

Monitoring the completion of the task by all students in the group, analyzing the performance of the work, making comments as the work progresses and obtaining specific results.

4. Homework (5 min): material from the electronic textbook on the topic, repetition of previously studied material.

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Basic metalworking operations and tools used

Straightening is an operation through which unevenness, curvature or other imperfections in the shape of workpieces are eliminated.

The main equipment for manual straightening of metals are steel or cast iron leveling plates. Used as a tool for manual editing steel hammers with a round striker; hammers from soft materials used for straightening final processed surfaces, as well as for straightening blanks and parts made of non-ferrous metals and alloys.

Chopping is an operation of cold metal cutting. The impact tools for chopping are metalworking and pneumatic hammers, and the cutting tools are chisels, cross-cutters and groovers.

Chisel. The metalworking chisel is made of tool carbon steel. It consists of three parts: shock, middle and working.

The striking part is made tapering upward, and its top (the striker) is rounded; The middle part of the chisel is held during chopping; the working part is wedge-shaped. The sharpening angle is selected depending on the hardness of the material being processed.

For the most common materials, the following sharpening angles are recommended: for hard materials(hard steel, cast iron) – 70°;

for materials of medium hardness (steel) – 60°;

for soft materials (copper, brass) – 45°;

For aluminum alloys– 35°.

Kreutzmeisel. To cut out narrow grooves and grooves, use a chisel with a narrow cutting edge - a cross-section. Such a chisel can also be used to remove wide layers of metal: first, grooves are cut with a narrow chisel, and the remaining protrusions are cut off with a wide chisel.

Locksmith's hammers. Bench hammers are used for chopping metals and come in two types: with a round head and with a square head. The main characteristic of a hammer is its mass. For chopping metals, hammers weighing 400...600g are used.

To make work easier and increase productivity, mechanized tools are used. Among them, the most common is the pneumatic chipping hammer.

Metal cutting

For cutting metal, hacksaws are used, the cutting part of which is the blade. The choice of blade depends on the material of the workpiece, its shape and size. Pipe cutters are used to cut pipes manually. For cutting sheet metal up to 1.5 mm thick, straight cutting or for figure cutting scissors. The wire is cut with needle-nose pliers or power scissors.

Filing

Filing is an operation in which a layer of metal is removed from the surface of the workpiece using a cutting tool - a file.

The purpose of filing is to give parts the required shape, size and specified surface roughness.

Files vary in the number of cuts, section profile and length.

According to the number of teeth cut per 10 mm of length, files are divided into 6 classes (0, 1, 2, 3, 4.5).

Depending on the work performed, files are divided into the following types: metalworking files – general purpose and for special works, machine, needle files and rasps.

1) General purpose metalworker’s files according to GOST 1465-69 are manufactured in eight types: flat, square, triangular, semicircular, rhombic and hacksaw with a length of 100 to 400 mm with a notch No. 0-5.

Bench files for special work are intended for removing very large allowances when filing grooves, shaped and curved surfaces; for processing non-ferrous metals, non-metallic materials, etc. Depending on the work performed, files of this type are divided into grooved, flat with oval ribs, bars, double-ended, etc.

2) Machine files according to their design are divided into rod, disk, shaped heads and lamellar. During operation, the rod file is subject to a reciprocating motion, the disc files and shaped heads are subject to rotational motion, and the plate files are subject to continuous movement along with a continuously moving metal strip.

3) Needle files according to GOST 1513-67 are manufactured in ten types: flat, triangular, square, semicircular oval, hacksaw, etc., 40, 60 and 80 mm long with a notch of 5 numbers. The length of the file is determined by the length of the working part. The edges of flat files have a single or double notch. The sides and top edge of hacksaw files have a double notch.

Needle files are used for filing small surfaces and narrow places that are inaccessible to processing with bench files.

4) Rasps, in accordance with GOST 6876-54, are manufactured in several types: general purpose, shoe and ungulate.

Depending on the profile, general purpose rasps are divided into flat, round and semicircular with notch No. 1-2 and length from 259 to 350 mm.

Hole machining

Drilling is carried out on drilling machines or using hand-held devices. The main cutting part is the drill, which has two cutting edges. When drilling holes with a diameter of more than 20 mm, pre-drill the holes with a drill of a smaller diameter, then drill it to size with a drill of a larger diameter.

After drilling, stamping, casting, they are countersinked to obtain a more accurate hole. Depending on the accuracy and purpose of the holes for their processing, countersinks of two numbers are made: No. 1 - for preliminary processing of holes and No. 2 - for final processing. Structurally, countersinks are of two types: solid, processing holes from 10 to 40 mm, and mounted ones, from 32 to 80 mm.

Reaming is used to produce holes with a more precise shape and low roughness. The operation is carried out using a multi-bladed tool - a reamer. Depending on the shape, cylindrical and conical reamers are distinguished. By method of application - manual and machine, by design - solid, mounted, sliding (adjustable) and combined, right and left.

Manufactured part:

Part sketch:

Progress:

1. Processing with a bastard file sharp corners blanks.

2. Applying markings using a caliper and a height gauge.

3. Punching along the contour of the marking for drilling.

4. Drilling.

5. Beating off excess material with a chisel.

6. Processing with files until the required dimensions are obtained.

7. Drilling out the central hole and thread. Thread cutting,

8. Polishing with sandpaper.

Welding section

infopedia.su

Plumbing operation - Great Encyclopedia of Oil and Gas, article, page 1

Locksmith operation

Page 1

Locksmith operations must be carried out very carefully, using only well-sharpened tools.

Mechanical operations performed on a conveyor are mechanized whenever possible.

Metalworking operations involve processing and fitting parts manually using simple tools and devices. For many years, locksmith operations were not mechanized and were therefore very labor intensive.

Mechanical assembly operations involve processing and fitting parts using simple tools. The need for metalworking operations is caused by imperfect machining of parts and the lack of interchangeability of parts during assembly.

The listed plumbing operations are preparatory; they are performed before assembling parts into assemblies.

An electrician performs plumbing operations for repairing electrical equipment.

An electrician performs plumbing operations for repairing electrical equipment using metalworking (Fig. 2), metal-cutting (Fig. 3) and measuring (Fig. 4) tools.

A metalworking operation is a completed part of the technological process of processing a workpiece or part, performed simultaneously and continuously before moving on to processing the next workpiece or part. The concept of metalworking operation is conditional, since the same metalworking operation carried out at different enterprises or in different conditions, is determined differently from the point of view of the technology for its implementation.

The most common plumbing operations during pipe preparation for assembly are threading and bending.

When performing metalworking operations on processing individual parts, they must be firmly secured in a vice. The bench vise must be in full working order, firmly clamp the products, and there should be no noticeable wear on the notches on the jaws.

Many metalworking operations in electrical machines differ significantly from similar operations in mechanical engineering.

Many metalworking operations in electrical machines differ significantly from similar operations in general mechanical engineering.

Variety of locksmith operations prompts improvement and specialization clamping fixtures, some of them are shown in Fig.

Pages: 1 2 3 4

www.ngpedia.ru

- Metalwork and tool work

Metalworking operations before assembly

Metalwork and tool work

Metalworking operations before assembly

Before assembling the device, the completeness, quality of workmanship and degree of readiness of the parts received for assembly are determined. Having made sure that the parts comply with the drawing and the technological process, they begin their metalworking.

Their machining involves dulling sharp edges, removing burrs, threading threads, assembling individual units installed in assembled form, creating the required connection and smooth running of parts and units, scraping or grinding the supporting planes and planes of connection with the body of the device. Most of the listed works are performed using conventional plumbing techniques.

In many cases, the processing of hardened surfaces of parts is carried out not by the mechanical department, but by the assembly section of the workshop. The reason for this is that grinding operations, as a rule, are interspersed with metalworking operations, and sometimes carried out by the same toolmakers. The hardened surfaces of device parts are ground on machines, with mechanized tools or manually.

Grinding in progress abrasive wheels, heads and bars. Manual grinding with stones is carried out if the surface of the part cannot be processed on a machine. It uses abrasive bars of various shapes and sizes (GOST 2456-52), made from both artificial and natural abrasive materials. It is known that during manual grinding the cutting speed (the speed of movement of the block) is many times lower than the cutting speed when grinding on machines or mechanized tools. In this regard, abrasive bars are selected with a greater hardness than grinding wheels. Manual grinding, as a rule, is carried out first with coarse-grained and hard stones, and then with fine-grained and softer stones.

During manual grinding, the surfaces of the bars quickly wear out, become greasy or lose their shape. To restore the shape and performance of the bars, they are periodically straightened on special plates coated with grinding powders. When straightening, the block is placed on the surface of the slab and moved in different directions with some pressure. After several movements along the surface of the slab, the plane of the bar becomes geometrically correct, and its edges become sharp and suitable for further work.

Abrasive stones are used to grind the shaped surfaces of copiers, installations and other parts, as well as the supporting surfaces of assembled devices. Methods of obtaining shaped surfaces, precise planes and angles are similar to the techniques outlined earlier. However, due to the fact that the accuracy of these surfaces is coarser than the equivalent surfaces of the measuring tool, in the production of devices they rarely resort to pattern finishing, and are more often limited to polishing the surfaces with abrasive sandpaper after mechanical or manual grinding.

The largest volume of preparatory metalworking operations falls on the metalworking of the device body. As stated earlier, the base and base planes of the body are machined before it is sent for assembly. At the assembly site, these surfaces are again inspected, their correctness is checked and damage is repaired. The test is carried out “for paint” using a control plate. The main and technological bases of the building are subjected to the same check.

The accuracy of the device requires a reliable connection between the housing and the components installed on it. Therefore, their connecting surfaces are carefully processed within the range of VV 6 - WV 8 by grinding or scraping. In addition to the necessary cleanliness of the surface, these planes are required to be strictly parallel and perpendicular to the base and bases of the body.

pereosnastka.ru

Main types of locksmith operations.

Production Main types of metalworking operations.

Marking.

Mechanic's workplace.

Topic 25. Basics of plumbing.

1. Locksmith work - ϶ᴛᴏ manual processing of materials, fitting of parts, assembly and repair of various mechanisms and machines.

A workplace is a part of the production area with all the equipment, tools and materials located on it that are used by a worker or a team of workers to complete a production task.

The workplace must occupy the area necessary for the rational placement of equipment and the free movement of the mechanic during work. The distance from the workbench and shelving to the mechanic should be such that he can use predominantly hand movements and, if possible, avoid turning and bending the body. The workplace should have good individual lighting.

A workbench (Fig. 36) is the main equipment of the workplace. It is a durable metal or wooden table, the cover (tabletop) of which is made of boards 50...60 mm thick hard rocks wood and covered with sheet iron. Single-seat workbenches are the most convenient and common, since on multi-seat workbenches, when several people work simultaneously, the quality of precision work is reduced.

Rice. 36 Single metal workbench:

1 – frame; 2 – tabletop; 3 – vice; 4 - protective screen; 5 – tablet for drawings; 6 – lamp; 7 – shelf for tools; 8 – tablet for working tools; 9 – boxes; 10 – shelves; 11 – seat

The tools necessary to complete the task are placed on the workbench. The drawings are placed on a tablet, and the measuring instruments are placed on the shelves.

Under the workbench tabletop there are drawers, divided into a number of cells for storing tools and documentation.

To secure the workpieces, a vice is installed on the workbench. Considering the dependence on the nature of the work, parallel, chair and hand vices are used. The most widely used are parallel rotary and fixed vices, in which the jaws remain parallel when opened. The rotating part of the vice is connected to the base with a center bolt, around which it can be rotated to any angle and secured in the required position using a handle. To increase the service life of the vice, steel overhead jaws are attached to the working parts of the jaws. Chair vice They are rarely used, only for performing work involving impact loads (for cutting, riveting, etc.). When processing small parts, a hand vice is used.

Selecting the height of the vice according to the height of the worker and rational placement of the tool on the workbench contribute to better development of skills, increased productivity and reduced fatigue.

When choosing the installation height of the vice, bent at the elbow left hand placed on the jaws of the vice so that the ends of the straightened fingers touch the chin. Tools and devices are placed so that they can be conveniently taken with the appropriate hand: what is taken right hand- hold on the right, what is taken with the left - on the left.

A protective screen made of metal mesh or durable plexiglass is installed on the workbench to contain pieces of metal flying off during chopping.

Blanks, finished parts and fixtures are placed on racks installed in the area allocated for them.

2. Marking is the operation of applying lines (scores) to the workpiece, defining (according to the drawing) the contours of the part and the places to be processed. Markings are used for individual and small-scale production.

Markings are carried out on marking plates cast from gray cast iron, aged and precisely machined.

Lines (marks) for planar markings are applied with a scriber, for spatial markings - with a scriber fixed in the clamp of the planer. Scribblers are made from steel grades U10 and U12, their working ends are hardened and sharpened.

The center punch is designed for making recesses (cores) on pre-marked lines. It is made from steel grades U7, U7A, U8 and U8A.

The marking compass is used for drawing circles, dividing angles and applying linear dimensions to the workpiece.

3. Main types of locksmith operations.

Chopping is a metalworking operation in which excess layers of metal are removed from a workpiece using a cutting and impact tool, grooves and grooves are cut out, or the workpiece is divided into parts. The cutting tools are a chisel and a crosspiece, and the impact tool is a hammer.

Cutting is the operation of separating metals and other materials into parts. Taking into account the dependence on the shape and size of the workpieces, cutting is carried out with a hand hacksaw, hand or lever scissors.

Hand saw consists of a steel solid or sliding frame and a hacksaw blade, which is inserted into the slots of the heads and secured with pins. A handle is attached to the shank of the fixed head. A movable head with a screw and a wing nut serves to tension the hacksaw blade. The cutting part of a hacksaw is a hacksaw blade (a narrow and thin plate with teeth on one of the ribs), made of steel grades U10A, 9ХС, Р9, Р18 and hardened. Use hacksaw blades with a length (distance between holes) of 250-300 mm. The teeth of the blade are spread (bent) so that the width of the cut is slightly larger than the thickness of the blade.

Metal straightening is an operation in which unevenness, dents, curvature, warping, waviness and other defects in materials, workpieces and parts are eliminated. Editing in most cases is a preparatory operation. Straightening has the same purpose as straightening, but defects are corrected in hardened parts.

Bending is widely used to give workpieces a certain shape in the manufacture of parts. For straightening and bending manually, straightening plates, straightening headstocks, anvils, vices, mandrels, sledgehammers, metal and wooden hammers (mallets) and special devices are used.

Riveting is a metalworking operation of connecting two or more parts with rivets. Rivet connections are permanent and are used in the manufacture of various metal structures.

Riveting is performed in a cold or hot (if the rivet diameter is more than 10 mm) state. The advantage of hot riveting is that the rod better fills the holes in the parts being joined, and when cooled, the rivet tightens them better. When riveting in a hot state, the diameter of the rivet should be 0.5...1 mm smaller than the hole, and in a cold state - 0.1 mm.

Manual riveting is performed with a hammer, its weight is selected depending on the diameter of the rivet, for example, for rivets with a diameter of 3...3.5 mm, a hammer weighing 200 ᴦ is required.

Filing is a metalworking operation in which a layer of metal is cut off from the surface of a part with files to obtain the required shape, size and surface roughness, to fit parts during assembly and prepare edges for welding.

Files are steel (steel grades U13, U13A; ШХ13 and 13Х) hardened bars of various profiles with teeth cut on the working surfaces. The file teeth, which have a cross-sectional shape of a sharpened wedge, cut off layers of metal in the form of shavings (sawdust) from the workpiece.

Scraping is usually called the operation of scraping thin layers of metal from the surface of a part with a cutting tool - a scraper. This is the final processing of precision surfaces (guide frames of machine tools, control plates, plain bearings, etc.) to ensure a tight fit. The scrapers are made from steels U10 and U12A, their cutting ends are hardened without tempering to a hardness of HRC 64...66.

Lapping and finishing are operations of surface treatment with especially fine-grained abrasive materials using laps.

These operations achieve not only the required shape, but also the highest accuracy (5...6th quality), as well as the lowest surface roughness (up to 0.05 microns).

Fitting and assembly work - ϶ᴛᴏ installation and dismantling work performed during the assembly and repair of machines. The various connections of parts made during machine assembly are divided into two basic types: mobile and stationary. When performing plumbing and assembly work, a variety of tools and devices are used: wrenches (simple, socket, sliding, etc.), screwdrivers, drifts, pullers, devices for pressing and pressing.

Locksmith. Plumbing practice

Locksmith

A specialist in processing metal blanks, manufacturing and repairing parts or metal products and many other types of work performed using hand and power tools, mainly in the process of assembling and adjusting devices, mechanisms, machines, and equipment. The range of locksmith work is so wide and varied that in the manufacturing sector, locksmiths, as a rule, specialize in one particular profile: for example, plumbers, toolmakers, pattern makers, assemblers, machine tool repairmen, car mechanics, etc.

The word "locksmith" is of German origin. Translated into Russian, it means “specialist in the manufacture of locks.” Obviously, historically, the locksmith profession has its origins, its roots in housework. Indeed, during the renovation and improvement of a city apartment, construction rural house There is a constant need for a variety of metal products: strips, brackets, overlays, squares for frames, all kinds of fasteners, etc. Not all of these products are and are not always on sale. But even if there are, it is often more profitable to make them yourself than to buy them in a store. In addition, individual products may be of an original design, i.e. are suitable only for this specific case and, of course, cannot be purchased in a store or on the market. The manufacture of such products requires significant skills in metal processing with hand and mechanized tools at home. These skills are based on knowledge of the properties of metals, their processing technology, working and measuring tools and work methods.

Together with gem, and in rural house, and in a city apartment different Appliances: devices, mechanisms, machines. In order for these devices to work well and reliably, it is necessary to constantly monitor their serviceability, conduct timely preventive inspections, clean and lubricate rubbing parts, replace worn parts, i.e. carry out appropriate repairs. All this also requires skills in processing metals and other materials. Moreover, repairing equipment requires knowledge of the equipment itself, the laws and principles of its operation, i.e. a certain general technical literacy. Consequently, in this case, the home craftsman acts as a repairman.

Basic locksmith operations

Locksmith technology includes the performance of individual locksmith operations in the manufacture or repair of metal parts or products. A metalworking operation is understood as influencing a metal workpiece with a hand or mechanized tool in order to obtain a finished part or connect parts into a whole product. These are, for example, filing workpieces, drilling holes, etc.

Locksmith operations can be divided into processing, assembly, finishing and auxiliary. With the help of processing operations, the shape and size of the workpieces are changed. These include metal cutting chisel, metal cutting scissors or hacksaw, straightening and bending of metals, metal filing, thread cutting etc. Assembly operations are, for example, performing threaded connections. Among finishing operations, grinding and polishing of workpiece surfaces occupy a significant place. Auxiliary operations include marking, control and measurement operations. The simplest control and measuring instruments used when performing plumbing operations at home are measuring ruler, metalworker square, calipers. To measure angles, you can use a regular school protractor. These instruments are familiar to everyone from school.

The manufacture of a product usually begins with markings. It is performed using a control and measuring instrument. Such a tool is also used when performing other plumbing operations; for example, each processing operation must be followed by checking the correctness of its execution using various control and measuring tools.

Metal blanks and parts are not only cut, but also connected to each other. For this purpose, in addition to threaded connections, use riveting, soldering And welding, although the latter, like heat treatment of metals, are usually not classified as plumbing work.

The techniques and tools used when working with metal are also suitable when working with plastics. So, for example, the most common and accessible plastic material - organic glass - can be sawed with a hacksaw, jigsaw, filed with a file, cut with a homemade cutter, drilled, etc.; When heated, organic glass can be bent, cut with scissors, and given various shapes under pressure using wooden blocks as a matrix and a punch. Spacer washers are machined from getinaks; foil (single- and double-sided) getinax is suitable for making at home printed circuit boards, instrument housings, shielded blocks (in this case, the walls and partitions of the blocks are connected by soldering). Fastening posts, bushings, rollers, tool handles and other parts can be machined from textolite rods. Bakelite plates are cut out, then filed and drilled into circuit boards for electrical devices.

Tools and accessories for performing various plumbing operations

Operation	Tools and accessories
Measuring and marking	Steel ruler, scale ruler, caliper, measuring compass (with sharp ends), calipers, square, protractor, scriber, center punch
Drilling holes	Drill with manual drive or electric drill, twist drills, countersink, countersink, reamer
Fastening and clamping	Bench and hand vices, clamps, round nose pliers, pliers, pliers
Impact works	Hammer, mallet
Riveting (manual)	Support, tension, crimping
Chopping and cutting metal	Chisel, crosscut, hand shears for cutting sheet metal, hacksaw, slotting, lever shears
Filing	Files: bastard, personal, velvet; square, flat, triangular, round, rhombic
Threading	Sets of taps and dies, devices for thread cutting (drivers, die holders, die holders)
Screwing and unscrewing	Screwdriver sets, wrenches, adjustable wrench
Soldering and tinning	Soldering tool (soldering iron, blowtorch, soldering torch), scraper, cleaner, wire brush, soldering flares

Workplace of a home mechanic

At home, to perform plumbing work, it is advisable to have a separate metal workbench - metal or upholstered metal sheet wooden table with tool boxes. If there is no special workbench, then the easiest way is to adapt an old utility table as a workplace. A large load on the table during operation usually requires more solid foundation. If necessary, the table legs are strengthened from the outside or inside using screwed wooden planks or metal corners. On the sides and back, the table legs are strengthened crosswise with screwed boards. The normal thickness of a utility table cover is about 20 mm, but this may not be enough for plumbing work. It is recommended to make a second cover (slab) from 30 mm thick boards and fasten it from below with screws to the old cover. The plate should protrude beyond the edges of the table on all sides by approximately 50 mm so that a clamp or sharpening machine, screw on the vice, etc. Metal corners are screwed to the plate - from below, from the side and/or from the front - so that the part can be processed. Despite robust construction, the desktop may become loose and move during operation. Therefore, it is advisable to place it in a corner of the room and attach it with metal corners or strips to the floor or wall; The cover can be screwed to a strip on the wall. Electric current should be supplied to the workplace through two separate electrical circuits: one - for electric tools and machines, the other - for lighting (light on workplace should fall from the front!). Several sockets mounted on the wall allow you to use different devices at the same time.

Among the devices, the craftsman will first of all need stationary and manual ones. vice, anvil, straightening plate, and thread cutting tools- die holders, collars, clamps. A set of plumbing tools required in a home workshop: hammers, used as percussion instrument when cutting, bending, straightening, riveting; ticks - for capturing, holding, moving workpieces, cutting wire and other operations; set files - for filing metals; chisel - for cutting off metals, cutting off old rivets, etc.; taps And dies - for cutting internal and external threads, respectively; drill- for drilling holes; metal hacksaws and scissors - for cutting metal. The set of tools and accessories required for a home workshop is given in the summary table.

The workplace should provide the opportunity to perform a variety of plumbing work (and not only plumbing). The replenishment of the workshop with tools, various devices and materials necessary for work usually occurs gradually, depending on the type of work performed, as well as on the tastes and inclinations of the master. Ready-made tool sets can be purchased at the store. For those who are starting small and want to purposefully expand their existing arsenal of tools, it is useful, and in some cases necessary, to direct their efforts to making individual tools and devices on their own. Homemade tools and devices are not in all respects equivalent to their industrial counterparts, but they are quite suitable for the needs of the home craftsman.

Here are some typical examples homemade instruments and devices. Not every craftsman has an anvil or a straightening plate in his house. They can be successfully replaced with appropriately processed pieces of railway rail, channel, or I-beam (Fig. 1).

Rice. 1. Homemade devices for a metalworking workshop: 1, 2 - unprocessed and processed pieces of I-beam; 3 - processed piece of channel; 4 - processed piece of rail.

Lips are a safety device for a vice when clamping soft, fragile parts or parts with a polished surface. Material: sheet aluminum 1...2 mm thick. The sizes of the jaws are determined by the size of the vice. Using a scriber or pencil, draw a line on the workpiece, from which all dimensions are measured or set aside (Fig. 2). You can use handheld tin snips to cut soft aluminum. To cut hard aluminum, use a hacksaw. To ensure that the hacksaw blade does not slip off the marking line, an auxiliary line is made near this line with a triangular file and sawed along it. When cutting, the workpiece must be strengthened in a vice using squares. Bend the workpiece, securing it in a vice, and using a mallet, bring the angle between the sides of the jaws to 90 °C.

Rice. 2. Lipsticks: 1 - marking of the mouthpiece blank; 2 - clamping the workpiece in a vice using jaws when cutting it with a hacksaw; 3 - general form mouthpieces.

A scriber is a tool for drawing marking lines. Material: steel rod with a diameter of 3 or 4 mm and a length of approximately 200 mm. Using pliers (Fig. 3), bend an eye with a diameter of about 25 mm. The working end of the scriber is sharpened using a fine-grained sandpaper. The tip is hardened: it is heated on a gas burner until it acquires a cherry-red color (temperature approximately 700...800 ° C), dipped in water, as a result it becomes so brittle (hard) that it can break off. The hardness is reduced by tempering: after cleaning with fine-grained sandpaper, the tip is again heated to a light yellow tarnish (temperature approximately 200 ° C), dipped into water again and then cleaned with fine-grained sandpaper.

Rice. 3. Scribbler: 1 - appearance; 2 - bending the eyes with round nose pliers.

A gauge (template) for checking sharpening is a device for checking the sharpening angle of a center punch or chisel. Material: sheet steel approximately 2 mm thick. Having completed the marking, the workpiece is cut out with a hacksaw, corner slots are cut out in it (Fig. 4), which are then processed (finished) with a file. To check the accuracy of filing, triangles are first cut out of cardboard, which correspond in size to the slots of the gauge. The triangles are inserted into the slots of the gauge and examined in the light: if the cuts are correct, then only thin strips of weak light of uniform width between the walls of the slot and the sides of the triangles will be visible.

Rice. 4. Caliber (template) for checking sharpness (1); checking the sharpening angle of the chisel (2) with a gauge.

Screwdrivers with curved ends (Fig. 5) are used for tightening and unscrewing screws in cases where this is inconvenient or impossible to do with an ordinary screwdriver. Material: tool steel rod with a diameter of 7 mm or a nail of the same diameter. Having sawed off the workpiece required length, both ends are bent (it is recommended to bend the steel in a heated state), filed, then subjected to hardening and tempering in the same way as a scriber.

Rice. 5. A screwdriver with bent ends, made of a steel rod (1) and a nail (2).

Materials

Strips of steel sheets, parts of used bicycles, baby strollers, electric stoves, refrigerators, wall clock and other devices, old screws, nuts, metal angles, tubes, rods, springs, pieces of wire, etc. - all this can be used by a home mechanic in the manufacture of various parts and products. Thrift and a developed ability to determine the usefulness of one or another “junk” item are necessary qualities of a home craftsman. It is important, without turning your home workshop into a cluttered closet, to determine a place for each future workpiece so that you can easily find it at the right time.

A home mechanic most often has to deal with processing various steel workpieces. If they are on sale, they are in a limited assortment. As a rule, it is necessary to use secondary raw materials. In this case, it is important, firstly, to be able to determine the grade of steel at home, secondly, to know what steel of this grade is suitable for, and thirdly, through heat treatment, learn to give the material the required mechanical properties(hardness, ductility, etc.).

The grade of steel can be determined quite accurately by the resulting beam of sparks on the emery wheel. The presence of alloy additives significantly changes the properties of the steel itself. For example, containing both chromium and nickel in steel increases its toughness and hardness; the presence of nickel alone makes the steel not only tough, but also gives it the ability to withstand large shock loads; Alloyed chromium and silicon additives make the steel tough and easier to heat treat.

When using recycled materials, it is important to know the grades of steel used to make the most common tools. Sometimes a tool that has fallen into disrepair can be made into a new, useful one. Below is a list of steel grades used for the manufacture of certain tools:

Glands from carpentry tools 9HF

Chisels, screwdrivers, stamps for steel U7A

Cores, woodworking tools U10, U10A

Hammers, sledgehammers, smoothers, carpentry tools U7

Taps UP, P9, 9ХС

Needle files U10-U12

Files U10-U13, ШХ6

Hacksaw blades Р9, Р18, ШХ15

Hand saw blades. . . . U8-U12

Wood saws U8GA

Knives of jointing machines 9Х5ВФ

Circular saws 85ХФ

Sawmill frame saws 85ХВ

Cross saws U8GA, U10

Rip saws 85Х

Dies 9ХС

Bow saw blades U8GA, 85HF

Punches, dies, punches U8, U8A

Manual reamers P9, 9ХС

Machine reamers P9, P18

Cutters for hard metals U13, U13A

Turning and planing cutters U10, U10A

Twist drills for wood 9ХС, 9Х5ВФ

Metal drills P9, P18

Milling cutters P9, P18

Scrapers U12, U12A

When processing metal blanks, the home craftsman needs to master the techniques of heat treatment of metals. For example, unhardened (“raw”) steel is quite ductile: it can be sawed, filed, forged, chopped, straightened, etc. Hardened steel is extremely hard: it can only be processed with an abrasive tool.

Not all metals and metal alloys can be combined to create any kind of structure. Some metals and alloys are incompatible with each other: in the places of their joints, when moisture enters, so-called galvanic (electrical) vapors are formed, which cause increased corrosion of the metal (alloy), weaken the mechanical strength of the joints and break electrical contacts. For example, unalloyed steel is incompatible with copper and copper alloys and compatible with aluminum, tin, chromium, zinc; copper is incompatible with aluminum and aluminum alloys, zinc and is compatible with tin, nickel, chromium; zinc is incompatible with copper and copper alloys and is compatible with steel, aluminum, tin, nickel, chromium. Taking into account this property of metals, in particular screws, rivets and other fastening material used to connect metal parts should be selected from metals that are homogeneous or compatible with these parts.

Lit.: Hirte V., Do it yourself 1000 things, trans. from German, M., 1970; Verkhovtsev O.G., Lyutov K.P., Amateur Master in Electrical Engineering and Electronics, L., 1984; Makienko N.I., General course in plumbing, 2nd ed., M., 1984; Arbuzov M.O., Handbook of a young repairman, M., 1985; Starichkov B.S., Workshop on metalwork, 4th ed., M., 1985; Syuch J., ABC of the home master, trans. from Hungary, M., 1985; House and Estate, M., 1989; Mokretsov A.M., Elizarov A.I., Plumber practice, M., 1989; Handbook of labor training. A manual for students in grades 5-7, M., 1992; Erlykin L.A., House and plot. Book set “Do it yourself”, book. 3, M., 1993.

Profession of a locksmith.

Metalworking refers to work performed with hand and mechanized tools and completing the manufacture of most products through fitting and finishing work, connecting various parts into assembly units, kits and complexes and adjusting them.

Assembly mechanics assemble various machines and mechanisms. Maintenance and their repairs during operation are carried out by repairmen. Toolmakers provide production with the necessary tools, facilitate and improve machining. Mechanics installing equipment, devices, communications securely install them in the proper place, bring different kinds energy and basic and auxiliary materials necessary for production. All these workers have in common the ability to perform various metalworking operations. They learn this in a general locksmith course.

The degree and type of professional training, the availability of knowledge, skills and abilities and suitability to perform work of a certain content and complexity determine the qualifications of the worker. It is assessed by a tariff category, which is assigned to the worker by a qualification commission. The basis for this is the qualification characteristics given in special tariff and qualification reference books. It states what the worker “must be able to do” and what he “must know” in order to receive the appropriate tariff category for his specialty.

Basic locksmith operations.

Let's look at the basic metalworking operations using the example of processing simple parts - a guide key (Fig. 1). Like the wine from the drawing, all surfaces of the key are processed; it has three holes: two stepped for fastening screws and one with threads.

The key is made from keyed steel - a rod of rectangular cross-section. To obtain a workpiece of the required length, produce marking – scriber draw lines on the surface of the circle that determine the shape and dimensions of the part. Further chisel(the operation is called chopping) or hacksaw (cutting) the workpiece is separated. During the cutting process, the workpiece may be bent. She needs to be straightened out. Often you need to do the opposite: bend having a workpiece, give it a complex shape. Then execute bending.

With the above operations it is impossible to obtain correct form surfaces of the part and specified dimensions. They are preliminary, preparatory. Their purpose is to prepare the workpiece for subsequent processing, ensure and speed it up by removing large layers of metal. To give the key the desired shape and dimensions of the workpiece cast . Hole ø 11 mm and M10 thread receive drilling , and local expansion of the hole size to ø 17 mm – countersinking. Thread in the drilled hole is threaded tap. When a hole must have precise dimensions, it deploy . Except

considered, there are other operations: sawing And fitting– obtaining holes of complex shapes and very precise processing of two parts being connected; scraping And lapping– precise final operations ensuring high precision and tight connections; riveting, soldering And gluing– operations that allow connecting parts together to form permanent connections.

As can be seen from the above, all operations for the manufacture of any product must be carried out in a certain

sequences. Together they make up technological process processing the part.

Metalworking technology contains a number of basic operations, such as marking, chopping, straightening and bending of metals, metal cutting, filing, drilling, countersinking, countersinking and reaming of holes, threading, riveting, lapping and finishing, soldering etc. Most of these operations relate to metal cutting.

3.1 Marking

Marking is the operation of applying lines (scores) to the surface of the workpiece, showing, according to the drawing, the contours of the part or place to be processed. Markup is divided into:

Linear (one-dimensional) – along the length of rods, rolled products, strip steel,

Planar (two-dimensional) – for sheet metal blanks,

Spatial (volumetric, three-dimensional) – for volumetric workpieces.

Special marking tools include scribers, center punches, marking compasses, and surface planers. In addition to these tools, hammers, marking plates and auxiliary devices are used: pads, jacks, etc.

Figure 6 Scribbler

Scribblers (Figure 6) are used to draw lines on the marked surface of the workpiece. They are made from tool steel U10 or U12 (hardness HRC 58-62).

Center punches (Figure 7) are used for applying recesses (cores) to previously

Figure 7 Kerner

marked lines so that the lines are clearly visible and are not erased during the processing of parts.

Kerner – this is a rod made of tool carbon steel U7, U8 (HRC 52-57) with a length of 100-160 mm and a diameter of 8-12 mm. The sharpening angle is usually 60°, for more precise markings - 30-45°, for the centers of future holes - 75°.

Marking (metal) compasses The design is similar to drawing compasses.

Reismus (Figure 8) is used for applying parallel vertical and horizontal marks. Recently, a height gauge with a sharp tip has been used more often.

Planar and especially spatial marking of workpieces is carried out on marking plates.

Marking plate - this is a cast iron casting, the horizontal working surface and side edges of which are very precisely machined.

Template called a device by which parts are made or checked

3.2 Straightening and bending of metals

Editing is an operation to eliminate defects in workpieces and parts in the form of concavity, convexity, waviness, warping, curvature, etc. Its essence lies in the compression of the convex layer of metal and the expansion of the concave one.

The metal is straightened both in cold and heated states. The choice of one or another straightening method depends on the amount of deflection, size and material of the workpiece (part).

Straightening can be done manually (on a steel or cast iron leveling plate) or machine (on leveling rollers or presses).

Correct plate , just like the marking one, must be massive. Its dimensions can be from 400400 mm to 15003000 mm. The slabs are installed on metal or wooden supports, ensuring the stability of the slab and its horizontal position.

For straightening hardened parts (straightening) use straightening headstocks. They are made of steel and hardened. The working surface of the headstock can be cylindrical or spherical with a radius of 150-200 mm.

Manual straightening is carried out with special hammers with a round, radius or insertable soft metal striker. Thin sheet metal rules mallet(with a wooden hammer).

The straightening is checked “by eye”, and if there are high requirements for the straightness of the strip, with a straight edge or on a test plate.

Shafts and round workpieces of large cross-section are straightened using a manual screw or hydraulic press.

Bending metals is used to give the workpiece a curved shape according to the drawing. Its essence lies in the fact that one part of the workpiece is bent relative to the other at a given angle. Manual bending is done in a vice using a hammer and various devices.

Bending of thin sheet metal is carried out mallet .

When plastic deformation of metal occurs during bending, the elasticity of the material must be taken into account: after the load is removed, the bending angle increases slightly.

Pipe bending is done with or without filler (usually dry river sand). The filler protects the pipe walls from the formation of folds and wrinkles (corrugations) in places of bending.